Blender Game not rendering models correctly, normals recalculated and flipped,
I figured out what was going on after a few hours of trial and error, the issue was that the faces that weren't displaying had more than 4 vertices, once I triangulated the faces everything worked fine. The issue with some other textures disappearing depending on different culling and normal settings was due to the object being scaled in the negatives on the y-axis, blender doesn't like that apparently.